edit: this does not work on the next Qubes release (R4.1) (see here)
Whisker menu is awesome (compared to the default XFCE one) and it doesn’t even have to be installed (it’s already there)
I think it’s comes already be installed on the system. So you can follow the following guide (from the
Add the Whisker menu to your XFCE panel part only)
Then you can also replace the “whiskers” icon with the qubes icon. Right-clicking on the whisker menu icon » properties » Icon
And then at the top of the window that pops up you select
Location Icons and then there should be 4 little “Q” icons (blue, green, red and yellow/orange).